Nadal vs. Fish: Having spent nearly five hours on court the day before, the second seed will find his powers of recovery severely tested if he seeks to continue his mastery over the top-ranked American. Burdened with a similar task in Chennai after an epic victory over Moya three years ago, Rafa faded quickly against Youzhny a day later. Uncharacteristically erratic during much of his twelfth straight victory over Verdasco, Nadal now targets his seventh consecutive victory over Wimbledon quarterfinal victim Fish. A finalist at his last three tournaments, the American regrouped swiftly from his Rogers Cup disappointment to conquer Davydenko and Gasquet without losing his serve in either match. Failing to serve out a match against Benneteau, Nadal’s service frailty extended into his grinding battle with Verdasco. In few other departments does Fish surpass the Spaniard, however, while the latter’s crackling passing shots will challenge him on approaches or serve-volley gambits. Despite his improved stamina, he still cannot attempt to outrun or outmaneuver the Spaniard, as he should have learned in his Wimbledon loss. Strikingly, though, the American’s most successful Masters 1000 tournament has proven Nadal’s least successful, the only event of this stature where he has not reached the final. An unexpected loss to Baghdatis in a 2010 quarterfinal extended that futility and snapped an unbeaten streak against that distinctly inferior foe, whereas Fish’s second finals appearance here followed from victories over Murray and Roddick. Nowhere else would he seem more likely to ambush Rafa, moreover, than on a fast hard court in his home nation with the ten-time major champion still searching for confidence.

Federer vs. Berdych: Into their first meeting this year, both men will bring memories of their three notable collisions in 2010. Bookending Berdych’s upset of Federer at Wimbledon, their two Masters Series encounters ended in third-set tiebreaks that they split in Miami and Toronto. The two-time defending champion has looked arguably the most formidable player in the men’s draw this week, exacting revenge for his 2009 losses to Del Potro with superb serving. Less remarkable was a predictably comprehensive victory over Blake that left the GOAT’s energies minimally depleted for Friday. Yet Berdych also impressed by losing just four games in his last three sets, two of them against world #11 Almagro. Still seeking his first Masters 1000 semifinal of the season, the Czech may feel liberated by the prospect of a second half in which he defends relatively few points. Both players often rely on running around their backhands to strike inside-out forehands to the opponent’s backhand, so the battle for the middle of the baseline will prove critical. Despite the Cincinnati humidity, Federer has looked especially agile and keen of instincts this week, while his effective returning of Del Potro’s serve bodes ill for Berdych. Relying on that shot to set up his heavy groundstrokes, the eighth seed needs to assert himself early in rallies before Federer outmaneuvers him and disrupts his rhythm.

Djokovic vs. Monfils: Precisely a week ago, they met in a quarterfinal at the Rogers Cup that scarcely felt like a battle between two top-10 players. A battle it was not, in fact, for Djokovic won ten of the last eleven games from the disengaged Frenchman and improved his record against him to 7-0. While the world #1 pockmarked the baseline with his groundstrokes, Monfils focused on entertaining the crowd the occasional improbable retrieval or dramatic, leaping smash. Even more unpredictable than his compatriot Tsonga, he has begun to win the matches that he should win more often but continues to lose almost all of the matches that he should lose. Clearly intimidated by Djokovic’s almost error-free play, Monfils lamented after last week’s debacle that he had no weapons with which to challenge the Serb. A more accurate account would ascribe that outcome not to his lack of weapons but to his reluctance to use them. Noted by former coach Roger Rasheed, Monfils’ curious passivity has prevented him from exploiting his offensive potential to the utmost, necessary against elite foes. A casual, loose-limbed eccentric, he enjoys rallying endlessly from behind the baseline too much to finish points at the first opportunity or in a manner less than artistic. Although still a pleasure to watch, Djokovic’s more functional, efficient style requires opponents to adopt a similarly determined, gritty mentality in order to challenge him—something of which Monfils rarely seems capable.

Simon vs. Murray: Both preferring to defend rather than attack, these quarterfinalists display similarly symmetrical groundstrokes and an aversion to risk. Relying on high-percentage shot selection and stingy consistency to frustrate Ferrer, Simon has vaulted into the threshold of the top 10 as he has distanced himself from the injuries that hampered him last season. Quarterfinals in Dubai and Miami have accompanied two minor titles, telegraphing the Frenchman’s renewed presence just outside the elite group of contenders. Losing his last six encounters with Murray, however, Simon has suffered from the disparity between their first serves. When the Scot gains at least a modest success rate on that shot, he can prevent his service games from developing into the wars of attrition that the Frenchman’s service games often become. When the percentage dips, the rest of his game can spiral downwards, as his opening win over Nalbandian illustrated. Surely relieved to have avenged his Miami loss to Bogomolov, Jr. with a 12-ace barrage on Thursday, Murray needs a sturdy week in Cincinnati before the next Slam arrives. He has much more to lose than to gain in this match, which suggests that tentative ball-striking might define it. On the other hand, his nemeses typically overpower rather than outlast him, and Simon’s legs may have grown weary following consecutive three-setters filled with epic rallies.

Sharapova vs. Stosur: Winless in eight clashes with the statuesque Siberian, Stosur has found her indifferent backhand exposed and her kick serve neutralized by this opponent. Normally jumping above the comfort level of most WTA returners, the latter shot leaps into Sharapova’s strike zone and allows her to hit down on the ball, flattening it into a powerful point-starting blow. The three-time major champion has won the last nine sets that they have played by exploiting the asymmetry in Stosur’s groundstrokes, which contrasts with her weaponry on both wings. After a third-round exit in Toronto, Sharapova recaptured glimpses of her spring form with a resounding victory over Kuznetsova, who has the innate athleticism and elastic movement that has troubled programmatic shot-makers like Maria. Like that Roland Garros champion, the former Roland Garros finalist will hope to hit as many forehands as possible but must avoiding exposing too much court to her opponent’s lasers. Unlike Kuznetsova, Stosur can create significant pressure with her opening shot, finishing points as swiftly and decisively as Sharapova does when she has the opportunity. Since neither player wishes to spend the morning patrolling the baseline, most exchanges should end with an aggressive blow from one player or the other that permits her slow-footed opponent no time to restart the rally. In two relatively uneventful victories this year, Sharapova delivered that terminal blow much more often than did Stosur, and decided the clear majority of points on her own terms. On the fast surface where she reached the final last year, the WTA’s most fearsome returner will aim to assault both first and second serves, requiring the Aussie to summon all of the confidence accumulated during her run to the Rogers Cup final.

Hantuchova vs. Zvonareva: Aided by Bartoli’s 16 double faults, Hantuchova nevertheless deserved credit for outlasting the tenacious double-fister in a match that lasted exactly three hours. Dazzling in her two 2011 meetings with Zvonareva, the elegant Slovak halted the Russian’s title defense in Pattaya City before nearly forestalling her title run in Doha. On both of those occasions, her clever angles tested Zvonareva’s lateral movement and drew her away from her safe haven along the baseline into uncomfortable positions. Notoriously fragile in close matches, Hantuchova predictably faded late in the third set of their Doha thriller, and fatigue from Thursday might compromise her energy. Meanwhile, the second seed has continued an encouraging post-Wimbledon surge with a pair of routine victories. As she prepares to defend her US Open final, Zvonareva would benefit immensely from an impressive week in Cincinnati, where the fast courts would seem to undermine her naturally counterpunching style. On the other hand, the relaxed atmosphere of the American Midwest may soothe her easily ruffled emotions, deflating whatever pressure she encounters.

Petrova vs. Petkovic: Saturated with drama was their only previous encounter, which thundered into a third-set tiebreak at last year’s US Open. Although her prime lies several years behind her, Petrova remains an occasionally formidable force on serve and at the net, skills that have aided her in doubles as well as singles. Overcoming Ivanovic in the second round, the College Park champion can feel fortunate to have avoided Wozniacki a round later, dispatching the Dane’s latest nemesis with scant difficulty. Unlike her opponent, Petkovic fought her way to this quarterfinal over compelling opposition in Gajdosova and Wimbledon champion Kvitova, whom she has defeated in consecutive weeks after struggling against her early in 2011. Neither the Russian nor the German plays with much margin for error, suggesting that viewers will see significant quantities of unforced errors if their timing falters. While Petkovic rarely has earned the opportunity to reach a semifinal at an event of this significance, Petrova will realize that she can expect few more such chances as her career wanes. More dominant from her forehand than her backhand, the world #11 will aim to target her opponent’s forehand, less reliable than her two-hander. The stolid veteran and the cheeky upstart should offer an intriguing contrast of personalities in a match that should prove well-contested and compelling, if not star-studded or aesthetically picturesque.

Peng vs. Jankovic: Doubtless buoyed by her three-set triumph over Schiavone, Jankovic showcased some of her finest tennis this season, including imaginatively angled passing shots, alert anticipation, and timely serving (although facing 19 break points). Although she twice failed to serve out the match against the indomitable Italian, the former #1 ultimately reveled in avenging her reverse at this opponent’s hands in Roland Garros. More revenge might lie ahead with Australian Open conqueror Peng aligned to intercept the Serb, but Jankovic has lost their only two meetings since 2008. Victorious in their six preceding encounters, however, she smothered Peng with her balanced groundstrokes and a court coverage that comfortably withstood the Chinese star’s meager power. Amidst the most impressive season of her career, the world #15 has achieved that career-high ranking by winning nearly 50 matches not long after the year’s midpoint. Peng typically bombards the center of the baseline with her groundstrokes, attempting to elicit errors from opponents pressed into a position that prevents them from creating angles. Not likely to succumb to such a tactic when at her best, though, Jankovic more often relies upon similarly heavy north-south hitting that wears down the durability and patience of her victims. Once again flashing her signature smile towards the end of her hard-earned Schiavone victory, the 2009 Cincinnati champion has not won a title this year after having won at least one notable tournament in each of the previous four seasons. Can Jankovic muster just enough momentum to unleash an unexpected charge here?